In recent years a definite redefinition of what is considered to be a desirable snack food has occurred. Nutritious, wholesome, healthy snacks (e.g., those which are low calorie, low fat, and/or low salt) are becoming more and more popular.
Fresh fruit and vegetables have always been popular snack items but have the disadvantages of being somewhat inconvenient and messy to eat. Furthermore, since fruits and vegetables only stay fresh for a relatively short time, they must be purchased frequently.
Thus, there is currently a growing demand for healthy snack products which are nutritional, low in calories, fat-free or low in fat, low in salt, and which are shelf stable and convenient to eat.
Dried fruit products are well-known. Recipes teaching methods for drying fruit in the home are common. Such methods generally involve drying the product to a reduced moisture state either in an oven or in the sun. This results in soft, shrunken, rubbery pieces of fruit which have a poor eating quality. A variety of commercially dried fruit products are also available. These products are dried to moisture levels of from about 3% to about 25%.
Methods for freeze drying or vacuum drying fruit are also known. These methods can provide fruit products which are dried to a firm cripsy state. One method for producing crisp, dry fruit products involves an explosion-puffing system such as that described in Sullivan et al., Journal of Food Science, 45(6), 1550-1555 (1980). The explosion-puffing is carried out at an elevated pressure and in a stream of super-heated steam. The water in partially dried fruit pieces is rapidly brought to a temperature above its atmospheric boiling point. When the pieces are instantly returned to atmospheric pressure, a fraction of the water flashes into steam, creating a porous structure. After being puffed, the fruit pieces are dried by conventional means to 3% moisture or less. The explosion-puffing restores the partially dried, concave, case-hardened fruit pieces to their normal size and shape but with a porous structure. A problem with this method is that the product produced is particularly susceptible to losing its crispness over a short period of time.
An alternative method for producing crisp, dry fruit products involves drying the product first in a conventional hot air dryer, then frying in oil, and finally, expanding by vacuum to produce a porous hardened snack. Such a method is disclosed in U.S. Pat. No. 3,962,355, Yamazaki et al., issued June 8, 1976. These products might be considered undesirable because of their high-oil content; in addition, the oil in the product tends to go rancid after extended periods of storage.
Strolle et al., Journal of Food Science, 35(4), 338-342 (1970), suggests a solution to the problem of the instability of the crispy texture of explosion-puffed fruit pieces. The improvement involves replacing most of the monosaccharides found naturally in the fruit with sucrose which has a much higher softening temperature in the amorphous glass state. See also U.S. Pat. No. 3,833,747, Cording et al., issued Sept. 3, 1974. Similarly, U.S. Pat. No. 4,514,428, Glass et al., issued Apr. 30, 1985, covers a fruit snack product which is made by thinly slicing apples on the cross section and steeping the apples in a sugar solution prior to rapid drying. This produces a crisp dry apple slice. U.S. Pat. No. 3,962,355, supra, also utilizes a method wherein a sucrose soaking step is used prior to vacuum frying to produce a porous hardened snack.
Weight Watchers Apple Snack.RTM., marketed by Weight Watchers Inc., is a snack product in the form of crisply dried, firm, apple cubes. This product has a very low A.sub.W, a low density, a light airy structure, and has no added fat or sugar. However, an undesirable characteristic of this product is observed upon eating. As the product is chewed and the structure is rehydrated, it becomes somewhat gummy and sticky.
Fruit products which include meringue are also known; see, for example, a recipe for Apple Snow from the Wise Encyclopedia of Cookery, New York: Grossett and Dunlap, 1980, page 21. Here beaten egg whites, baked apple which has been run through a sieve, and powdered sugar are combined. This product is served as and is not baked and dried. A recipe for Apple Confections from Goldstein, Darra, A La Russe/A Cookbook of Russian Hospitaity, New York: Random House (1983), page 292, discloses a confection comprising a mixture of steamed pureed apple, lemon juice, sugar, flavoring, and stiffly beaten egg white, which is baked in a slow oven (150.degree. F.) until dry (about 6 hours). A recipe for Double-A-Meringue from Taylor, Demetria, Apple Kitchen Cook Book, International Apple Institute, 1979, page 181, discloses a baked dessert comprising sliced apples, sugar and meringue. In this product the meringue is placed on top of the layered sliced apples, not mixed in with the apples.
Products comprising fruit shreds are also known in the art. Dried fruits in the form of shreds having various moisture levels are commercially available. These products do not, however, include sugar and meringue. One recipe for Apple Puffs (Perl, Lila, The Delights of Apple Cookery, New York: Coward-McCann, Inc., 1963, page 52) teaches the combination of shredded apple with stiffly beaten egg white, sugar, cinnamon and a relatively high level of flour. Tablespoonsful of the mixture are then dropped onto a hot, well-greased griddle and "fried" until golden brown. These Apple Puffs have a relatively high A.sub.W and are cooked by frying on a griddle, rather than being dried.
A variety of dried vegetable products are also known. Potato chips, comprising potato slices which have been cooked to a very crisp state by frying in oil, are a very popular snack item. However, these snacks are generally relatively high in fat and salt content. Freeze dried vegetables are also known, but are generally not considered to be particularly desirable snack food items.
The art does not describe fruit or vegetable-based snack products, as taught herein, which are light and crispy in texture, are low in calories, fat and salt, and which comprise an agglomeration of subdivided pieces of fruit or vegetable.
It is therefore an objective of the present invention to provide a nutritious, wholesome, low calorie, low- or no-fat, low-salt snack product comprised of dried fruit or vegetable pieces.
It is a further objective to provide a fruit- or vegetable-based snack product that is formulated so as to be convenient, easy to eat, and shelf stable for extended periods of time.
It is a further objective to provide a fruit- or vegetablebased snack product that is good tasting, light and crispy, and which disperses easily in the mouth upon chewing.
It is yet a further objective to provide a method for making a fruit- or vegetable-based snack product with these unique attributes.